Comment 8 for bug 558784

If this was a design choice, it's a poor design choice, if you ask me. Consider this use case: audio is being played, and mute is toggled because the audio is painfully loud. the audio source must then be stopped to turn the volume down, otherwise the user is forced to deal with the too-loud volume until the desired volume is reached. If I'm using some sort of remote control to adjust the volume, say an infrared remote, it may not be possible to quickly lower the volume while its un-muted (maybe someone walks in front of me while I'm using the remote and the volume-down action is stopped, causing me to hold the button down again, and causing everyone in the room to deal with the too-loud audio for a few more seconds). Plus, my great-grandmother isn't so great with the mouse, and forcing her to un-mute the audio before changing it effectively means she's going to stop the audio before un-muting so she doesn't have to deal with the too-loud audio while she's changing the volume level.

second use case where I can see this being a problem; when audio is automagically muted because a speaker/headphone change has been detected, saving me from possibly having way-too-loud audio coming out of my headphones, I'm forced to stop the audio, un-mute, then change the volume level, rather than just moving the slider and un-checking mute. I think one of the largest uses of the mute toggle is when audio is started and the volume was previously set too high for the new source. I'm certainly used to toggling mute, turning down the volume, and toggling mute again.